Filmstrip projector with synchronized sound

ABSTRACT

A FILMSTRIP PROJECTOR PROVIDED WITH SYNCHRONIZED AUDIO ACCOMPANIMENT. THE FILMSTRIP IS FRAMED TO A PROJECTION APERTURE BY A MANUALLY OPERABLE FRAMING MEANS. ONCE FRAMED, THE FILMSTRIP IS ADVANCED FRAME-BYFRAME BY A MOTOR DRIVEN FILM ADVANCE MECHANISM. THE AUDIO ACCOMPANIMENT IS CARRIED ON A DUAL TRACK AUDIO TAPE ONE TRACK OF WHICH CARRIES THE AUDIO ACCOMPANIMENT. THE REMAINING TRACK CARRIES CONTROL SIGNALS WHICH SERVE TO ACTUATE THE FILM ADVANCE MECHANISM TO MAINTAIN SYNCHONIZATION BETWEEN THE AUDIO TRACK AND FILMSTRIP. THE FRAMING DEVICE INCLUDES A CLUTCH FOR DISENGAGING THE FILM DRIVE MECHANISM FROM THE DRIVE MOTOR.

July 11, 1972 Filed Dec. 14, 1970 F. c. BADALICH ET AL 3,675,994

FILMSTRIP PROJECTOR WITH SYNCHRONIZED SOUND 5 Sheets-Sheet 1 July 11,1972 c. BADAL-ICH ETAL 3,575,994

FILMSTRIP PROJECTOR WITH SYNCHRONIZED SOUND 5 Sheets-Sheet 2 Filed Dec.14, 1970 1972 F. c. BADALICH ET AL 3,675,994

FILMSTRIP PROJECTOR WITH SYNCHRONIZED SOUND July 11 5 Sheets-Sheet 4Filed Dec. 14, 1970 m 0 Q5 WBN. MAR-\Y n 05 S I w 9% N3 03 g 9 umw o N NH mm m3 WWN J 72616771515: Rank 6 Badalich .1 fi Z002 er'lohny 1972 F.c. BADALICH ET-AL 3,675,994

FILMSTRIP PROJECTOR WITH SYNCHRONIZED SOUND 5 Sheets-Sheet 5 Filed Dec.14, 1970 NHH mom QQH WmH mmm JLU87JZ7TSI Rank C-BadaZZch,

KO lqaiv hn. r 2195 US. Cl. 352-163 i d States Patent O C;

3,675,994 Patented July 11, 1972 3,675,994 FILMSTRIP PROJECTOR WITHSYNCHRONIZED SOUND Frank C. Badalich, Chicago, and Roy H. Watterlohn,

Morton Grove, Ill., assignors to Bell 8: Howell Company, Chicago, Ill.

Filed Dec. 14, 1970, Ser. No. 97,859 Int. Cl. G03b 21/46 Claims ABSTRACTOF THE DISCLOSURE A filmstrip projector provided with synchronized audioaccompaniment. The filmstrip is framed with respect to a projectionaperture by a manually operable framing means. Once framed, thefilmstrip is advanced frame-byframe by a motor driven film advancemechanism. The audio accompaniment is carried on a dual track audio tapeone track of which carries the audio accompaniment. The remaining trackcarries control signals which serve to actuate the film advancemechanism to maintain synchronization between the audio track and thefilmstrip. The framing device includes a clutch for disengaging the filmdrive mechanism from the drive motor.

FILMSTRIP PROJECTOR WITH SYNCHRONIZED SOUND This invention generallyrelates to a filmstrip projector and more particularly to a filmstripprojector adapted for use with a recorder proving synchronized audioaccompaniment.

BACKGROUND OF THE INVENTION Filmstrip projectors are finding wideacceptance in the instructional as well as sales promotional fields.This media is especially suitable for such purposes in that it permitsthe presentation of selected illustrations for varying time periodsdepending upon their informational content thus conserving film. It willbe appreciated that the simultaneous performance of a synchronized audiopresentation greatly increases the interest and usefulness of the visualpresentation.

The illustrated embodiment is particularly suited for the projection of35 mm. film but lends itself to other sizes as well. A particularcharacteristic of 35 mm. filmstrip is that development standards are notwell formulated throughout the industry. In this regard the sprocketholes are not precisely located with respect to the individual framespreventing the indexing of the film frames with the projection apertureby means of the sprocket hole orientation. Further, since the filmsprocket holes are not precisely related to the position of the filmframes, the advancing mechanism must be relatively exact to ensuresuitable framing throughout the entire film roll.

A particular feature of the illustrated embodiment is the inclusion of atape recorder which supplies audio accompaniment as well as a controlsignal for automatically advancing the filmstrip from frame to frame insynchronism with the audio format. Additionally, the user is affordedthe option of preparing and editing his own filmstrips. This feature isaccomplished by the addition of a signaling oscillator the output ofwhich is appropriately recorded as a frame advancing signal. The mainobject of this invention is to provide an improved filmstrip projectorwhich includes means for providing synchronized audio accompaniment forthe film format.

Other objects and advantages of this invention will become obvious fromthe following description of a preferred embodiment when considered inconjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a full sectional view of afilmstrip projector including certain features of this invention;

FIG. 2 is a prospective view of cartridge featured in combination withthe projector illustrated in FIG. 1;

FIG. 3 is a prospective view of the cartridge of FIG. 2

disassembled to more clearly illustrate the features of the componentsthereof;

FIG. 4 is a full sectional view of the cartridge of FIG. 2 with theaudio cassette removed for clarity of illustration;

FIG. 5 is a sectional view of the cartridge of FIG. 2 taken along theline 55 of FIG. 4;

FIG. 6 is a prospective view of a portion of the filmstrip projectorillustrated in FIG. 1;

FIG. 7 is a sectional view of the projector taken along the line 7--7 ofFIG. 1';

FIG. 8 is an enlarged sectional fragmentary view of the projector ofFIG. 1 taken along the line 88;

FIG. 9 is a symbolic diagram of the circuitry utilized to control theprojector of FIG. 1.

BRIEF DESCRIPTION OF THE ILLUSTRATED EMBODIMENT General Briefly, therear screen filmstrip projector 10 illustrated in FIG. 1 is housedwithin a cabinet consisting of a cover 12 and a base 14. One wall of thecover is a rear projection .screen 16 upon which the images aredisplayed. Housed in the base is a dual track audio cassette taperecorder 18 of modified construction carrying a cartridge 20. Upon loading of the cartridge 20 within the projector 10 the first frame of thefilmstrip is manually framed with respect to a projection aperture 22 bya manually operable framing means 24. The projector 10 is energizedcausing the image of the frame centered in the projection aperture 22 tobe projected upon the screen 16. Simultaneously therewith, the taperecorder 18 is actuated starting the audio tape cassette play. Therecorder 18 provides audio accompaniment and by a first track carryingthe audio message as well as film advance control by means of signalsrecorded .upon a second track. Upon the occurrence of a control signal aframe advancing means 26 advances the filmstrip a single frame.

Serving to prevent jamming or tearing of the film, an interlock 28prevents removal of the tape recorder while the film is threaded throughthe project 10. Additionally, the projector 10 includes various otheroperational features which will hereinafter be more thoroughlydiscussed.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT CARTRIDGE Base Thecartridge 20 carried by the tape recorder 18 is particularly illustratedin FIGS. 2-5 and comprises a cover 30 and a base 32. The base 32includes a pair of adjacent parallel oriented cassette retaining walls34 which cooperate to securely receive a conventional audio tapecassette 36. To ensure that the cassette is held in position, aretaining spring 38 engages with a pair of spring guides 40 defined bythe outwardly disposed surfaces of the cassette retaining walls 34.Additionally, projecting from the lower surface of the base 32 are apair of downwardly depending alignment pins 42 which are received inholes defined by the body of the cassette. Support wall 48 of the base32 is provided with a pair of clearance apertures 46 which allow therecord drive spindles (not shown) to fully engage the drive spools 44 ofthe cassette.

The upper surface of the support wall 48 carries a pair of spaced filmguide rails 50 the upwardly disposed edges of which are arcuatelyshaped. The ends of the rails are secured to a curved front wall 52. Theinwardly disposed surface of the front wall 52 carries two spaced pairsof sprocket hole guides 54. Each pair is secured to the wall 52 adjacentone edge thereof and serves to assure positive drive of the film as willfurther be described. Secured to the outwardly disposed surfaces of thefilm guide rails 50 adjacent the front wall are locking bosses 56 whichare selectively maintained in cooperative engagement with cartridgecover 30. Secured to the base 32 adjacent the ends of the film guiderails opposite the locking bosses are a pair of triangular shaped hingesupports 58. Inwardly projecting from each of the hinge supports 58 arehinge pins 60 which cooperate with the cover to permit convenient accessto the interior of the cartridge 20.

Cover The cover 30 comprises a pair of side walls 62, a rear wall 64 anda top wall 66 which define a film cavity. Positioned within the cover 30and serving to maintain the film in proper relationship with respect tocartridge is a film retaining means in the form of a pair of arcuatelyshaped resilient springs 68. The springs are fabricated from elongatedmetallic strips or any other suitable material. One end of each of themetallic strips is turned in a reverse curve as at 70 which serves toprevent scratching of the film emulsion during passage of the film fromthe cartridge. The remaining ends of the metallic strips are bent in anabrupt reverse curve and are positioned within spring receiving slots 72molded in the rear wall 64 of the cover. Adjacent the spring receivingslots 72 in each side wall of the cover are hinge holes 74 which materwith the hinge pins 60 on the base 32. Further, locking holes 76 arepunched in the side walls 62 of the cover 32 and engage the lockingbosses 56 on the cover. The hinge so formed permits the cartridge 20 tobe conveniently opened and the locking means ensures against accidentalopening.

Rotationally supported within the cover 30 and serving to drive the filmthrough the cartridge is a film drive spool 78. The ends of the filmdrive spool 78 are journaled through apertures 80 cut in the side walls62 of the cover 30. The film drive spool 78 includes a central hub 82and a pair of parallel spaced flanges 84. Each of the flanges 84 carriessprocket teeth 86 spaced for engagement with the sprocket holes providedalong the margins of the film. The sprocket teeth 86 are so aligned withthe sprocket hole guides 54, previously described, that as the filmpasses through the cartridge the margin of the film rides along thesprocket hole guides 54 and ensures that the sprocket teeth 86adequately engage the film. The central portion of the hub 82 ishollowed to define a splined receiver 87 for engagement with the frameadvance 26 as will subsequently be further described. Mounted upon thetop wall 66 within the cover and adjacent the film drive spool 78 are apair of film spool guides 88 which prevent the film from improperlythreading about the drive spool 78, a situation which might occur as anatural result of the curl of the emulsion. Similarly, a guide strap 90is secured between the side walls 62 of the cover adjacent the drivespool 78 to ensure that the film will feed vertically from the cartridgerather than follow its natural curl.

Operation In use, the audio tape cassette 36 is positioned in thecompartment defined by the base 32 of the cartridge 20 and is retainedin place by the locking spring 38. The cartridge is swung open on itshinges and the film, in coiled form, forced into the film retainingsprings 68. The film is placed out to the film drive spool 78 where itis engaged with the sprocket teeth 86. The cover 30 is forced shut andlocked by the locking bosses 56 seating in the holes 76. In the closedposition, the film rests upon the guide rails 50 and engages thesprocket teeth 86 on the drive spool 78. The guide strap forces the filmagainst its natural curl, upward along a plane generally normal to thebase and thus facilitates threading through the aperture plates on thebase 14 of the projector cabinet.

PROJECTOR Propection system Maintained within the base of the cabinet isa projection system which comprises a bulb 92 mounted upon a bulbsupport channel 94, which in turn is secured to the walls 96 of anopaque light chamber. Reflecting the light toward a condensor lensassembly 98 is a reflector 100. The light passes through the film and isdirected by means of a light mirror 102 mounted upon an inner wall 104through a projection lens 106. The image is reflected by a firstreflecting mirror 108 mounted upon a mirror support stand 110 secured tothe surface of a chassis 112 mounted in the base. The image reflected bythe first mirror 108 is passed to a second reflecting mirror 114 whichis supported between adjacent cover walls subtending the included angleand therefrom directed to the projection screen 16.

Recorder As shown in FIG. 7, a pair of parallel, adjacently spacedsupport rails 116, which are longitudinally notched as at 118, serve toslidably receive a tape recorder drawer 115. The outer walls of thedrawer 115 are flared outwardly to define flanges which rest within thenotches 118 in the rails 11'6. Within the drawer 115 is seated the audiotape cassette recorder 18. The recorder 18 is adapted to receive thecartridge 20. As previously mentioned the lower portion of the cartridge20 carries an audio tape cassette 36, which is received by the recorderin a conventional manner. Securely retaining the recorder drawer 115 inposition within the base 14 of the cabinet is an interlock 28.

As shown in FIG. 1, interlock 28 includes a locking pawl 122 pivota-blysupported for rotational movement with respect to an inner wall 124 ofthe cabinet. The pawl 122 is seated within a notch 126 defined by thewall of the recorder drawer. Manual release of the drawer is by means ofa release knob 128 accessible from the front of the cabinet andconnected to the locking pawl 122 by a locking rod 130. Biasing thelocking pawl 122 in the locked position is a 'coil spring 132 resting ona support angle 134 through which the rod is journaled. Thus in responseto depression of the knob 128 the pawl 122 is rotated about its pivot ina counterclockwise direction as viewed in FIG. 1, releasing the drawerfor removal through an acess door 135. Serving to ensure secure seatingof the pawl 122 with respect to the drawer 115 and thus ensure that thecartridge is properly positioned with respect to the projection apertureis a biasing means 136. The biasing means 136 urges the recorder 18 andthus the drawer in which it is seated against the holding surface of thepawl 122. The biasing means 136 includes a plunger 138 about which ispositioned a coil spring 140. The plunger is journaled through amounting angle 142 secured to the floor of the base of the cabinet.Additionally, the pawl displaces an upwardly disposed surface 144 forcooperation with an interlock mechanism as will hereinafter be furtherdescribed.

After the audio tape cassette and film are fitted in place within thecartridge 20, the cartridge is loaded into the tape recorder andrecorder drawer is slid forward until the locking pawl 122 drops intothe notch 126 in the side wall of the drawer. The biasing means 136assures that the locking pawl 122 is properly seated with respect to thedrawer 115 and thus maintains proper orientation of the cartridge 20within the projector 10.

Film guide As the cartridge moves into position the film is cammedbetween a pair of spaced parallel operative plates 146 and 148 mountedon the inner wall 104 which define the projection aperture 22. Servingto ensure threading of the film between the plates 146 and 148 is aspoon shaped cam 149 secured to the forwardly disposed edge of the plate148. The film, due to the natural curl of the emulsion is forced againstthe cam surface and urged into position between the plates.

During projection, the film is advanced through a film chute 150 andthen into a storage retainer 152 as illustrated in FIG. 7. The film chue150 comprises a pair of slotted rails 154 which are positioned toreceive the film passing between the aperture plates. The rails aremounted on the inner wall 104 by mounting posts 156 the outer ends ofwhich are grooved. Serving to facilitate rapid removal of the film,should it become jammed during projection, is a locking means 158 whichcomprises a flat locking plate 160 having slotted openings 162. Theouter rail 155 is positioned upon the posts 156. The plate 160 is placedover and slidably secured to the grooved end support posts 156. The filmretainer 152 includes a pair of parallel disposed spaced ear shapedreceivers 155 which has a single turn coil spring 166 secured to itsinwardly disposed surface. The coil spring 166 ensures that the storedfilm will be maintained in a nest coiled condition.

Framing As previously mentioned, a particular characteristic of afilmstrip is that the development criteria are not well established andthe location of the sprocket hole perforations along the film margin hasno predetermined position with respect to the frames. Prior to automaticoperation, the first frame of the film is properly positioned withrespect to the projection aperture 22 by the framing means 24. Servingto facilitate manual operation of the framing means '24 is a framingknob 1'68 locked to a framing rod 170 passing into the base of theprojector. As illustrated in FIGS. 6 and 8 the rod is journaled throughthe inner support wall 104. Adjacent the inner end of the framing rod170 is a selectively engageable coupling in the form of a straight toothpositive clutch 172, including a tooth driver 174, and a slottedreceiver 176. The driver 174 is set to the framing rod 170 and theslotted receiver 176 is rotatably mounted to a support angle 178 by abushing 180 through which the rod 170 is slidably journaled.

Formed upon the closed end of the receiver is a wheel gear 182 engagedwith an idler gear 184 mounted on the bracket 178. The idler gear 184 inturn engages a framing gear 186 mounted upon a film drive shaft 188. Thefilm drive shaft 188 is journaled through the inner wall 104 of thecabinet by means of a sleeve bearing 190. One end of the drive shaft 188carries a tooth member 192 (FIG. 7) of a dog-clutch which engages thesplined receiver 87 of the cartridge as film spool 78 previouslydescribed. Mounted upon the drive shaft and selectively rotatable withrespect thereto is a drive gear 194. Positioned between the drive gearand the framing gear is a friction washer 196 of resilient materialforming a friction clutch. Wound about the drive shaft and maintained inplace with a C washer 198 secured to the rearward end of the drive shaft188 is a clutch spring 200*. The remaining end of the clutch springrides upon the face of a shoulder washer 202. The shoulder of the washer202 bears against the drive gear 194 thus assuring that during thenormal position of a spring loaded clutch arm 204 the drive gear 194drives the framing gear 186. The clutch arm 204 is pivotably supportedupon the upper surface of the chassis 112. The clutch defines an openingthrough which the shank of the shoulder washer 202 passes. Serving tobias the free end of the clutch arm toward the drive gear 194 is atorsion spring 206.

An inward push to the framing knob pivots clutch arm 204 clockwise asviewed in FIG. 8 engaging the lips of the washer and releasing the forcewhich maintains the gears 194 and 186 in frictional engagement. Theframing gear 186 and the drive gear 194 are free to independentlyrotate. The position of the clutch arm is adjustable by an adjustmentscrew 208 threaded through the free end of the clutch arm. Coil spring210 is positioned between the clutch arm and the screw head.

In use, the framing knob is forced into the base of the cabinet and thestraight tooth positive clutch 172 is engaged. Simultaneously, theclutch arm is rotated about its pivot in a clockwise direction as viewedin FIG. 8 releasing the driving frictional engagement between the drivegear 194 and the framing gear 186. Rotation of the knob 168 in itsdepressed position rotates the gear 182 and thence the idler gear 184which in turn rotates the framing gear 186. The driving member 192 ofthe dog clutch is carried upon the end of the drive shaft 188 forrotation therewith. Since the dog clutch is engaged with the splinedreceiver 8-7 of the film spool 78, the film is advanlced. The film isdriven between the operative plates 146 and 148 until the desired imageis framed.

Film drive The frame advance means 26 is particularly illustrated inFIG. 6 and is powered by a capacitive start reversible four pole rotorclutch motor 210. The motor includes a spring loaded rotor 212 which,during period of deenergization, is forced to a disengaged off-centerposition with respect to the armature. Secured to one end of the rotoris a coupling in the form of a cross-pin dog-clutch generally designatedby the numeral 214. Extending from end of the rotor and axially ofi-setis a single pin 216 which engages a cross-pin 218, passing normallythrough an indexing drive shaft 220. The shaft is journalled through adrive assembly support bracket 222. Secured to the shaft for rotation bythe motor is a worm gear 224.

Upon energization, the rotor 212 of the motor 210 is drawn into thefield of the armature. The magnetic centering of the rotor causes thecross-pin dog-clutch 214 to engage, thus driving the worm gear 224. Uponde-energization of the motor, the coupling is immediately released andthe rotor allowed to coast to a stop in disengagement. This particulararrangement is advantageous in that it allows the rotor 212 to coast toa stop without altering the position of the frame advance means 26. Apinion gear 226 is secured to an idler shaft 228 journaled in thebracket 222. Formed within the gear is the driving member 230 of aGeneva drive 232.

The Geneva driving member 230 includes a locking circle 234 and a drivepin 236 engaging a Geneva star 238 mounted upon an indexing drive shaft240 journaled through the bracket 222 and through the inner wall 104.The axis of the shaft 240 is normal to the axis of the motor drive shaft220. The Geneva star 238 is a fourpointed star so that each revolutionof the drive pin 236 will turn the drive shaft 240 through ninetydegrees. Secured to the drive shaft adjacent the inner wall 104 is anindexing shaft gear 242 which is engaged with the drive gear 194. Aspreviously mentioned, during normal operation the coil spring 200 forcesthe shoulder washer 202 against the drive gear 194 so that the gears 194and 186 are in frictional engagement. Upon energization of the motor,the Geneva drive pin 236 rotates in response to an actuation pulse, tobe further described, and the driving member 230 rotates off of itscenter position illustrated in FIG. 6. A cam 244 formed upon the drivingmember 230 engages the leaf of a normally closed microswitch 246. Themicroswitch holds the motor 210' energized through a complete revolutionof the driving member 230. As the Geneva 232 completes one incrementaloperation the cam 244 again opens the micro-switch deenergizing themotor causing the rotor 212- to be immediately released from thearmature field. The motor 210 dynamically brakes without causing anyadditional movement of the Geneva or interfering with the framingpreviously obtained. In this manner, after the initial frame has beenpositioned in the aperture 122 accurate framing is maintained throughoutprojection. After projection of the film, the motor 210 is reverseddriving the drive means 26- in the reverse direction thereby rewindingthe film back into the cartridge.

Rewind To prevent rewind of the film to the point that the film becomesdisengaged from the drive spool 78 of the cartridge and to facilitateimmediate replay without the need for manual framing, a rewind sensingmeans 248- is provided. In this regard, the start of the film, which ofcourse corresponds to the end of rewind, is cut with an elongatedsprocket hole or rather a series of two or three sprocket holes areconnected by cutting the lands between adjacent holes. The sensingapparatus on end of rewind includes feeler 250 which rides upon themargin of the film. The feeler 250 is journaled upon a support shaft252. The feeler carries a locking tab 254 as well as a micro-switchactuation arm 256. During normal movement of the film through theaperture 122, the feeler 250 rides along the film surface. The feeler250 is caused to rotate in a clockwise direction, as viewed in 'FIG. 6,thereby closing the normally open rewind micro-switch 258. During thismode of operation the locking tab 254 engages a locking tab 260 carriedby a recorder interlock feeler 262. The recorder interlock feeler 262 ispart of the film interlock 28. The feeler 262 is rotatable about theshaft 252 and biased toward the film by a torsion spring 264 (FIG. 1).The lower end of the feeler engages the locking surface 144 of the pawl122 preventing removal of the drawer. When the film returns to itscompletely rewound position, the feeler 250, which is biased by theinternal switch Spring acting through the micro-switch leaf, drops intothe elongated sprocket hole, opening the micro-switch 258 andde-actuating the motor, thus preventing further rewind. At this pointthe interlock feeler 262 is resting on the film emulsion preventingremoval of the drawer. In the event it is desired to remove the film,the framing knob 168 is pushed inwardly engaging the straight toothcoupling 172 and the film is rewound into the cartridge. The interlockfeeler 262 under the bias of the torsion spring 264 drops into theaperture 22, allowing the pawl 122 to be actuated for release of thedrawer 115.

Control circuitry With respect to FIG. 9, the tape recorder 18 ismodified to include a three-gang six position rotary switch 266 forpurposes of selecting the various modes of operation. The switch shaftis coupled to a recorder drive mechanism 266 of conventionalconstruction and serves to control the speed and direction of the tapetransport drive as determined by the position of the selector switch266. It will be appreciated that the various functions can bealternately selected by means of push-button switches interconnected bya locking cam, in a manner well known to those skilled in the art. Forpurposes of discussion the switch-gangs are designated as a motor gang270, a rewind gang 272 and a transducer head-gang 274. The tape recorderalso includes a conventional pick-up head, an amplifier and a speakersystem for playing back the audio accompaniment from the tapes audiotrack. However, for purposes of clarity, the conventional tape recordercircuitry has not been illustrated and will not be further described.

The wiper of the transducer gang 274 is connected to a control tracktransducer head 276 for pick-up and playback of the film advance controlsignals. The fixed contacts of the transducer gang in the play, forwardsearch, reverse search, rewind and off positions are interconnecteddirectly to the input of an amplifier 278. 'In the record position, thetransducer is connected directly to the output of an oscillator 280which is coupled by a capacitor 282 to the input of the amplifier 278.The oscillator is triggered by means of a multi-vibrator 284 which isactivated by a switch 286. The multi-vibrator 284 pulses on theoscillator 280 for a fixed period of time causing a pulse to be appliedto the amplifier which is recorded upon the control track of the tape.Thus, each time the filmstrip is to be advanced the switch 286 isdepressed triggering the vibrator 284 which activates the oscillator280'. The pulse is recorded on the control track of the tape and isapplied as a film advance pulse to the amplifier 278. The output of theamplifier is connected to a noise filter 288 which is utilized duringplayback to eliminate noise transients on the tape from actuating apulse former 290. The pulse former 290 is coupled to the output of thenoise filter 288. The pulse former 290 is preferably a bistablemulti-vibrator actuated by the incoming audio pulse thus providing anoutput pulse of fixed duration independent of the duration of the inputsignal. The output of the pulse former 290 activates a single polenormally open relay 292. through a relay control 294.

As will be further discussed, the period of the pulse former 290 is suchthat the motor 210 is actuated for a period of time sufiicient to causethe cam surface 244 on the Geneva 23-2 to close the micro-switch 246 sothat the locking disc 234 will complete a single revolution before themotor is turned off. A fixed contact 296 of the relay 292 is connectedto the wiper of the motor gang 270 as well as to the rewind contact onthe rewind gang 272. The fixed contact 296 is also connected to a fixedcontact 298 of the motor hold micro-switch 246. The movable contact ofthe micro-switch 246 as well as the movable contact of the relay areconnected to one pole of an on or off power switch 300' as well as tothe wiper of the rewind gang 272. The remaining terminal of the on-offpower switch is connected to a power supply 302 and the remainingterminal of the power supply to the common motor terminal. The forwardlead of the motor is terminated at the record, play and forward searchcontacts of the motor gang 270 and the reverse lead through the end ofrewind micro-switch 258 to the reverse-search and rewind contacts of themotor gang.

OPERATION For purposes of discussion it will be assumed that a selectedfilmstrip is to be provided with audio accompaniment. The user seats thefilmstrip into the film retaining springs 68 of the audio visualcartridge cover 30 and routes the film so that the sprocket holesthereof engage the sprocket teeth 86 on the film drive spool 78. Thecover is locked by the locking bosses 56 engaging the locking holes 76in the cover and an erased audio-cassette cartridge is secured in placeby means of the retaining spring 38. The access door is opened, thedrawer lock knob 128 depressed releasing the locking pawl and therecorder removed from the cabinet. The cartrigde 20 is positioned in therecorder and the recorder 18 returned to the cabinet. The rear of therecorder 18 engages the biasing means 136 and the locking pawl 122 dropsinto the notch 126.

The user pushes the framing knob 168 against the action of the springbiased clutch releasing the drive gear 194 from frictional engagementwith the framing gear 186 and simultaneously engaging the straight toothpositive clutch 172. The knob is then rotated until the first frame ispositioned in the aperture 22 for projection. The knob is released andthe arm forces the clutch 172 out of engagement. The power supply isturned on by the switch 300 and the selector switch 266 placed in therecord mode.

The user records the desired audio-accompaniment for the frame beingprojected, and when it is desired to advance the frame, the switch 286is depressed actuating the multi-vibrator 284 which activates theoscillator 280* for a fixed period. The output of the oscillator 280 isrecorded upon the control track of the tape recorder 18 by means of thehead 276 and is also coupled through the capacitor 282 to the pulseformer 290 and relay control 294. The relay 292 is closed energizing themotor 210 which rotates in a forward direction. The relay 292 ismaintained closed for a duration corresponding to the pulse width fromthe pulse former 290 which is sufficient to assure closure of themicro-switch 246. The motor 210- continues to rotate the Geneva 232through a 90 movement which is correspondingly transmitted by means ofthe drive shaft 240 to the film drive spool 78. After a completerevolution, the switch 298 is opened by the cam 244 thus interruptingenergization of the motor 210. The spring bias on the rotor 212 of themotor 210 results in the immediate disengagement of the coupling 214allowing the motor to dynamically brake without altering the position ofthe film. This procedure is repeated until the entire filmstrip has beenprovided with suitable audio accompaniment.

Upon completion of the recording, the user rotates the switch 266 to therewind position. In the rewind position, the rewind gang 272 connectsone output terminal of the power supply to the wiper of the motor gangwhich in turn causes the motor to operate in the reverse direction in acontinuous manner until the end of rewind micro-switch 258 is opened bythe rewind feeler 250 dropping into the elongated sprocket holepreviously described. Upon com pletion of the rewind feature the film isin its start position and the tape recorder is allowed to come to rest.

Normal forward play is obtained by placing the selector switch 266 inplay position wherein th control track transducer 276 is connecteddirectly to the amplifier 278. Upon the occasion of advance signal, therelay 292 is momentarily closed energizing the motor 210 in the forwarddirection. The motor is held in energization for a complete revolutionof the Geneva locking disc 234 by the motor hold switch 246. When thenext successive frame reaches the projection aperture 122, themicro-switch 246 is opened de-energizing the motor.

The positioning of the selector switch 266 in the forward searchposition actuates the recorder drive mechanism 286 through themechanical coupling to a fast forward drive mode. In this position theaudio is garbled. However, the film advance pulses are fed to the motor210 and the filmstrip advanced in a rapid sequential fashion. When theoperator sees the desired frame upon the screen, he quickly places thecontrol switch in the play position and the projector continues itsnormal forward synchronized mode of operation.

In the reverse search position of the switch 266, the recorder drivemechanism 268 is switched to a fast reverse mode. The tape recorder thenoperates in a reverse direction and at each pulse the film drive motoris rotated in a reverse direction causing the film to backframe. Whenthe user sees the desired frame, he then 10 quickly interrupts thereverse search by placing the switch 266 in the play position or offposition. The projector is then ready for forward play.

While this invention has been particularly shown and described withreference to a preferred embodiment thereof it will be understood bythose skilled in the art that various changes in form and detail may bemade without departing from the spirit and scope of the invention.

What is claimed is:

1. In combination with a filmstrip projector including a light sourceand means for projecting an image at a projection screen, theimprovement comprising:

means for driving the filmstrip across a projection aperture, saiddriving means including a motor and a gear train, coupling said motor tothe film;

framing means coupled to said gear train for framing the filmstrip atthe projection station, said gear train including a releasable clutchcoupling said gear train to the film; and

means for releasing said clutch serving to uncouple the film from saidmotor, said clutch release means being actuated by said framing means soas to permit framing the film at the projection station independently ofsaid motor.

2. The apparatus of claim 1 wherein said gear train includes a Genevadrive, each incremental movement of said Geneva drive corresponding to asingle frame advance of said film.

3. The apparatus of claim 2 which further includes means for couplingsaid motor to said gear train upon energization of said motor.

4. The apparatus of claim 2, which further includes switching meanscoupled to said gear train for maintaining said motor energizedthroughout a predetermined operational movement of said gear train.

5. The apparatus of claim 4, wherein each incremental movement of saidGeneva drive corresponds to a single frame advance of said film, saidswitching means maintaining said motor energized for a durationcorresponding to said Geneva drive increment.

References Cited UNITED STATES PATENTS 1,291,275 1/ 1919 Ue-belmesser352--163 2,605,673 8/ 1952 Manderfeld 352-163 X 2,667,808 2/1954 Hart352-174 2,534,731 12/ 1950 Perillo 352163 X SAMUEL S. MATTHEWS, PrimaryExaminer M. L. GELLNER, Assistant Examiner US. Cl. X.R.

